1. Field of the Invention
The present invention relates to an information processing apparatus and method and, more particularly, to an information process for protecting the intellectual property right of input data.
2. Related Background Art
In recent years, as a method of transmitting a single bitstream by combining multimedia data containing a plurality of objects such as motion image data, audio data, and the like, so-called MPEG-4 (Moving Picture Experts Group Phase 4) is standardized. The receiver (player) of MPEG-4 plays back, e.g., motion image scenes in association with audio data. In such MPEG-4 player, various use limits must be imposed on some or all data to attain copyright protection and the like.
The aforementioned MPEG-4 datastream has a function of independently transmitting/receiving many video scenes and video objects on a single stream unlike in a conventional multimedia stream. As for audio data, many objects can be similarly restored from a single stream. That is, the MPEG-4 data stream contains BIFS (Binary Format for Scenes) that modifies VRML (Virtual Reality Modeling Language) as information for synthesizing these scenes. Note that BIFS is information that describes MPEG-4 scenes using binary data.
Since individual objects required for synthesizing scenes are transmitted after they individually undergo optimal coding, they are also individually decoded by the decoder, and scenes are synthesized and played back by synchronizing the time axes of individual data with that used in the player in accordance with the description in BIFS.
In this manner, since the MPEG-4 player synthesizes a plurality of objects, use limits based on the alleged copyright must be imposed on these objects. For this purpose, a system for obtaining authentication information pertaining to the use of copyrighted information in units of objects is proposed.
In general, in order to realize copyright protection, the transmitter must execute a process for encrypting data to be transmitted or embedding copyright information as a digital watermark in data to be transmitted.
The receiver, i.e., the player acquires information for decrypting (decoding) the encrypted data, or information required for authenticating the digital watermark when the user has paid a given fee for the copyrighted information, and decodes and plays back the data that have undergone the aforementioned process, and contain desired motion image data and audio data. Upon decrypting the encrypted data or authentication using the digital watermark, copyright protection is assured by limiting the number of times of copying of data or inhibiting a given object from being edited with other objects.
In this manner, the receiver decodes and plays back the received multimedia data after decryption or authentication using the digital watermark.
However, when copyright information is embedded as a digital watermark in multimedia data to protect the copyright, that copyright information embedded in the multimedia data cannot be extracted until the multimedia data is decoded.
Decryption can be done before the multimedia data is decoded. However, authentication of the digital watermark can be done only after the multimedia data is decoded. For this reason, the playback control of multimedia data protected by the copyright information must be able to cope with encryption or digital watermarking.